2020 Volvo VNL Bulb Size Guide

Quick reference

The 2020 Volvo VNL offers a range of lighting options, with many trucks coming equipped with advanced LED systems from the factory. However, some configurations still utilize traditional halogen bulbs, often in base models or specific trim levels. It's crucial to check your vehicle's specific build or owner's manual to confirm the exact bulb type and size, especially for headlights, as both halogen (typically H11 for low beam and H7 for high beam) and integrated LED units are common.

LED vs halogen upgrade considerations

Upgrading your 2020 Volvo VNL from halogen to LED bulbs can significantly improve visibility, modernize the truck's appearance, and reduce power consumption. However, there are several key considerations:

• CANBUS Errors: Modern vehicles like the Volvo VNL utilize a Controller Area Network Bus (CANBUS) system to monitor various electrical components, including lighting. When you replace a halogen bulb with an LED, the lower power draw of the LED can trick the CANBUS system into thinking the bulb is out, triggering a "bulb out" warning light on your dashboard. To circumvent this, you'll often need to install CANBUS-compatible LED bulbs or separate load resistors.
• Adapters and Fitment: While many aftermarket LED bulbs are designed for direct replacement, some may require additional adapters or housings to ensure proper fitment within the VNL's light assemblies. This is particularly true for headlight upgrades, where the LED bulb's larger heatsink may necessitate modifications.
• Beam Pattern: Not all LED bulbs are created equal. Poorly designed LED replacement bulbs can create scattered light patterns that are less effective than halogens and can blind oncoming drivers. Look for LED bulbs that mimic the filament placement of their halogen counterparts to ensure a proper beam pattern.
• Heat Dissipation: LEDs generate heat, but unlike halogens, they dissipate it from their base rather than the light-emitting surface. Effective heat dissipation is crucial for LED longevity. Make sure any aftermarket LED bulbs have adequate heatsinks or cooling fans.

How to replace each bulb

Replacing bulbs on your 2020 Volvo VNL generally requires basic hand tools and a bit of patience. Refer to your owner's manual for detailed, model-specific instructions and safety precautions. Always ensure the vehicle is turned off and cool before attempting any bulb replacement.

• Low Beam/High Beam: Access to these bulbs typically involves opening the hood and locating the back of the headlight assembly. For halogen bulbs, you'll usually twist and pull to remove the old bulb, then simply insert and twist the new one. For LED headlight assemblies, replacement is often a complete unit swap, which may require professional installation.
• Fog Lights: These are usually accessible from underneath the front bumper or by removing an inner fender liner. The process is similar to headlights: twist, remove, and replace.
• DRL (Daytime Running Lights): Depending on the setup, these might be part of the main headlight assembly or a separate unit. Access can vary, sometimes requiring removal of grilles or trim pieces.
• Front/Rear Turn Signals, Brake Lights, Tail Lights: For exterior lighting, you'll typically need to access the rear of the light housing, often from inside the trunk/faring or by removing the entire light assembly. Bulbs usually twist into a socket that then plugs into the housing.
• Reverse Lights: Similar to turn signals and brake lights, these are usually accessed from the rear of the tail light assembly.
• License Plate Lights: These are often small, easily accessible housings mounted above the license plate. You'll usually unclip or unscrew the lens to gain access.
• Side Markers: These small lights on the side of the truck are usually removed by gently prying them out or by unscrewing them from the fender.
• Dome/Map Lights: For interior lights, carefully pry off the lens cover using a plastic trim removal tool to avoid scratching the headliner or housing. The bulbs are often push-in style or festoon bulbs that simply clip into place.

Common lighting issues for this generation

Owners of the 2020 Volvo VNL may encounter a few common lighting-related issues:

• Intermittent Bulb Out Warnings: This is frequently related to the CANBUS system, especially if aftermarket LED bulbs have been installed without proper load resistors or decoders. The system detects the lower power draw and flags it as an open circuit.
• Headlight Condensation: Headlight assemblies can sometimes develop condensation inside, particularly in humid climates or after heavy rain. While a small amount can evaporate, persistent or excessive condensation can indicate a seal issue and may require replacing the assembly.
• Flickering LEDs: If you've upgraded to aftermarket LEDs, flickering can occur due to voltage fluctuations, incompatible CANBUS decoders, or poor quality LED drivers. Ensuring you use high-quality, CANBUS-compatible LEDs designed for heavy-duty trucks can help mitigate this.
• DRL Malfunctions: Issues with Daytime Running Lights can sometimes be traced back to wiring issues, faulty DRL modules, or simply a burned-out bulb in halogen setups.

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